The present invention relates to a recording system of variable length picture information, which is capable of recording picture information such as a document and which is capable of retrieving and outputting the recorded picture information as needed.
A conventional system for storing and retrieving a document picture is known wherein pictures reduced in scale are directly recorded on microfilms. As an improvement over this system, a picture information file device has been proposed which uses a 2-dimension scanning device utilizing photoelectric conversion techniques with a laser beam and CCD elements. This 2-dimension scanning device decomposes a document picture into picture elements, converts the picture elements into picture signals, and records the picture signals on a magnetic recording medium at a high density. This type of device also stores on the magnetic recording medium picture information and a retrieval title consisting of a retrieval code indicating a recorded location of the picture information and so on. Therefore, as the need arises, the retrieval code may be input to retrieve the corresponding document picture and output as a hard copy.
However, with this type of device, the length of the picture information may differ depending upon the size of the original. Furthermore, when compressing the picture information by MH (modified Hoffman) conversion for recording, the length of the picture information differs from one original to another. When the picture information recorded in this manner is of variable length, the recorded picture information may not be replaced with other picture information for the purpose of editing. When the length of the previously recorded picture information is shorter than the length of the picture information to be recorded in its place and the new information is recorded in place of this recorded picture information, other picture information may be adversely affected, that is, may be unintentionally converted to other picture information.